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Periodic table |
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The discoveries of the 118 chemical elements known to exist as of 2024 are presented here in chronological order. The elements are listed generally in the order in which each was first defined as the pure element, as the exact date of discovery of most elements cannot be accurately determined. There are plans to synthesize more elements, and it is not known how many elements are possible.
Each element's name, atomic number, year of first report, name of the discoverer, and notes related to the discovery are listed.
This article may overuse or misuse colour, making it hard to understand for colour-blind users.(March 2024) |
Periodic table by era of discovery | ||||||||||||||||||||||||||||||||||||||||
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1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | |||||||||||||||||||||||
Group → | ||||||||||||||||||||||||||||||||||||||||
↓ Period | ||||||||||||||||||||||||||||||||||||||||
1 | 1 H | 2 He | ||||||||||||||||||||||||||||||||||||||
2 | 3 Li | 4 Be | 5 B | 6 C | 7 N | 8 O | 9 F | 10 Ne | ||||||||||||||||||||||||||||||||
3 | 11 Na | 12 Mg | 13 Al | 14 Si | 15 P | 16 S | 17 Cl | 18 Ar | ||||||||||||||||||||||||||||||||
4 | 19 K | 20 Ca | 21 Sc | 22 Ti | 23 V | 24 Cr | 25 Mn | 26 Fe | 27 Co | 28 Ni | 29 Cu | 30 Zn | 31 Ga | 32 Ge | 33 As | 34 Se | 35 Br | 36 Kr | ||||||||||||||||||||||
5 | 37 Rb | 38 Sr | 39 Y | 40 Zr | 41 Nb | 42 Mo | 43 Tc | 44 Ru | 45 Rh | 46 Pd | 47 Ag | 48 Cd | 49 In | 50 Sn | 51 Sb | 52 Te | 53 I | 54 Xe | ||||||||||||||||||||||
6 | 55 Cs | 56 Ba | ![]() | 71 Lu | 72 Hf | 73 Ta | 74 W | 75 Re | 76 Os | 77 Ir | 78 Pt | 79 Au | 80 Hg | 81 Tl | 82 Pb | 83 Bi | 84 Po | 85 At | 86 Rn | |||||||||||||||||||||
7 | 87 Fr | 88 Ra | ![]() | 103 Lr | 104 Rf | 105 Db | 106 Sg | 107 Bh | 108 Hs | 109 Mt | 110 Ds | 111 Rg | 112 Cn | 113 Nh | 114 Fl | 115 Mc | 116 Lv | 117 Ts | 118 Og | |||||||||||||||||||||
![]() | 57 La | 58 Ce | 59 Pr | 60 Nd | 61 Pm | 62 Sm | 63 Eu | 64 Gd | 65 Tb | 66 Dy | 67 Ho | 68 Er | 69 Tm | 70 Yb | ||||||||||||||||||||||||||
![]() | 89 Ac | 90 Th | 91 Pa | 92 U | 93 Np | 94 Pu | 95 Am | 96 Cm | 97 Bk | 98 Cf | 99 Es | 100 Fm | 101 Md | 102 No | ||||||||||||||||||||||||||
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Z | Element | Earliest use | Oldest existing sample | Discoverer(s) | Place of oldest sample | Notes |
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6 | Carbon | 26000 BC | 26000 BC | Earliest humans | Charcoal and soot were known to the earliest humans, with the oldest known charcoal paintings dating to about 28000 years ago, e.g. Gabarnmung in Australia. [1] [2] The earliest known industrial use of charcoal was for the reduction of copper, zinc, and tin ores in the manufacture of bronze, by the Egyptians and Sumerians. [3] Diamonds were probably known as early as 2500 BC. [4] True chemical analyses were made in the 18th century, [5] and in 1772 Antoine Lavoisier demonstrated that diamond, graphite, and charcoal are all composed of the same substance. [1] In 1787, de Morveau, Fourcroy, and Lavoisier listed carbon (in French, carbone) as an element, distinguishing it from coal (in French, charbon). [1] | |
29 | Copper | 9000 BC | 6000 BC | Middle East | Asia Minor | Copper was probably the first metal mined and crafted by humans. [6] It was originally obtained as a native metal and later from the smelting of ores. Earliest estimates of the discovery of copper suggest around 9000 BC in the Middle East. It was one of the most important materials to humans throughout the Chalcolithic and Bronze Ages. Copper beads dating from 6000 BC have been found in Çatalhöyük, Anatolia [7] and the archaeological site of Belovode on the Rudnik mountain in Serbia contains the world's oldest securely dated evidence of copper smelting from 5000 BC. [8] [9] Recognised as an element by Louis Guyton de Morveau, Antoine Lavoisier, Claude Berthollet, and Antoine-François de Fourcroy in 1787. [1] |
82 | Lead | 7000 BC | 3800 BC | Asia Minor | Abydos, Egypt | It is believed that lead smelting began at least 9,000 years ago, and the oldest known artifact of lead is a statuette found at the temple of Osiris on the site of Abydos dated around 3800 BC. [10] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [1] |
79 | Gold | Before 6000 BC | Before 4000 BC | Levant | Wadi Qana | The earliest gold artifacts were discovered at the site of Wadi Qana in the Levant. [11] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [1] |
47 | Silver | Before 5000 BC | ca. 4000 BC | Asia Minor | Asia Minor | Estimated to have been discovered in Asia Minor shortly after copper and gold. [12] [13] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [1] |
26 | Iron | Before 5000 BC | 4000 BC | Middle East | Egypt | There is evidence that iron was known from before 5000 BC. [14] The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in about 4000 BC. The discovery of smelting around 3000 BC led to the start of the Iron Age around 1200 BC [15] and the prominent use of iron for tools and weapons. [16] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [1] |
50 | Tin | 3500 BC | 2000 BC | Asia Minor | Kestel | First smelted in combination with copper around 3500 BC to produce bronze (and thus giving place to the Bronze Age in those places where Iron Age did not intrude directly on Neolithic of the Stone Age).[ clarification needed ] [17] Kestel, in southern Turkey, is the site of an ancient Cassiterite mine that was used from 3250 to 1800 BC. [18] The oldest artifacts date from around 2000 BC. [19] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [1] |
51 | Antimony | 3000 BC | 3000 BC | Sumerians | Middle East | An artifact, said to be part of a vase, made of very pure antimony dating to about 3000 BC was found at Telloh, Chaldea (part of present-day Iraq). [20] Dioscorides and Pliny both describe the accidental production of metallic antimony from stibnite, but only seem to recognize the metal as lead. [21] The intentional isolation of antimony is described in the works attributed to the Muslim alchemist Jabir ibn Hayyan (c. 850–950). [22] In Europe, the metal was being produced and used by 1540, when it was described by Vannoccio Biringuccio. [23] Described again by Georgius Agricola De re metallica in 1556. Probably first recognised as an element by Lavoisier in 1787. [1] |
16 | Sulfur | Before 2000 BC | Middle East | Middle East | First used at least 4,000 years ago. [24] According to the Ebers Papyrus, a sulfur ointment was used in ancient Egypt to treat granular eyelids. (The Ebers papyrus was written c. 1550 BC, but is believed to have been copied from earlier texts.) [25] [26] Designated as one of the two elements of which all metals are composed in the sulfur-mercury theory of metals, first described in pseudo-Apollonius of Tyana's Sirr al-khaliqa ('Secret of Creation') and in the works attributed to Jabir ibn Hayyan (both 8th or 9th century). [27] Designated as a universal element (one of the tria prima ) by Paracelsus in the early 16th century. Recognized as an element by Lavoisier in 1777, which was supported by John Dalton in 1808 and confirmed by Joseph Gay-Lussac and Louis Jacques Thénard in 1810. [1] | |
80 | Mercury | 1500 BC | 1500 BC | Egyptians | Egypt | Cinnabar (the most common mineral form of mercury(II) sulfide, HgS) was used as a pigment from prehistory, dating as far back as the 9th millennium BC in the Middle East. [28] Cinnabar deposits in Turkey, exploited from 8000 years ago, also contain minor amounts of mercury metal. [29] Found in Egyptian tombs dating from 1500 BC. [30] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [1] |
30 | Zinc | Before 1000 BC | 1000 BC | Indian metallurgists | Indian subcontinent | Used as a component of brass since antiquity (before 1000 BC) by Indian metallurgists, but its true nature was not generally understood in ancient times. A 4th century BC vase from Taxila is made of brass with a zinc content of 34%, too high to be produced by cementation, providing strong evidence that metallic zinc was known in India by the 4th century BC. [31] Zinc smelting was done in China and India around 1300. [1] Identified as a distinct metal in the Rasaratna Samuccaya around the 14th century of the Christian era [32] and by the alchemist Paracelsus in 1526, [33] who gave it its present name and described it as a new metal. [1] P. M. de Respour isolated it from zinc oxide in 1668; [1] the first detailed documentation of zinc isolation was given by Andreas Sigismund Marggraf in 1746. [34] |
78 | Platinum | c. 600 BC – AD 200 | c. 600 BC – AD 200 | Pre-Columbian South Americans | South America | Used by pre-Columbian Americans near modern-day Esmeraldas, Ecuador to produce artifacts of a white gold-platinum alloy, although precise dating is difficult. [35] A small box from the burial of the Pharaoh Shepenupet II (died around 650 BC) was found to be decorated with gold-platinum hieroglyphics, [36] but the Egyptians may not have recognised that there was platinum in their gold. [37] [38] First European description of a metal found in South American gold was in 1557 by Julius Caesar Scaliger. Antonio de Ulloa was on an expedition to Peru in 1735, where he observed the metal; he published his findings in 1748. Charles Wood also investigated the metal in 1741. First reference to it as a new metal was made by William Brownrigg in 1750. [39] |
33 | Arsenic | c. AD 300 | c. AD 300 | Egyptians | Middle East | The use of metallic arsenic was described by the Egyptian alchemist Zosimos. [40] The purification of arsenic was later described in the works attributed to the Muslim alchemist Jabir ibn Hayyan (c. 850–950). [22] Albertus Magnus (c. 1200–1280) is typically credited with the description of the metal in the West, [41] though some question his work and instead credit Vannoccio Biringuccio, whose De la pirotechnia (1540) distinguishes orpiment from crystalline arsenic. The first to unquestionably have prepared metallic arsenic was Johann Schröder in 1641. Recognised as an element after Lavoisier's definition in 1787. [1] |
83 | Bismuth | c. 1500 [42] | c. 1500 | European alchemists and Inca civilisation | Europe and South America | Bismuth was known since ancient times, but often confused with tin and lead, which are chemically similar. The Incas used bismuth (along with the usual copper and tin) in a special bronze alloy for knives. [43] Agricola (1530 and 1546) states that bismuth is a distinct metal in a family of metals including tin and lead. This was based on observation of the metals and their physical properties. [1] [44] Miners in the age of alchemy also gave bismuth the name tectum argenti, or "silver being made" in the sense of silver still in the process of being formed within the Earth. [45] [46] [47] Beginning with Johann Heinrich Pott in 1738, [48] Carl Wilhelm Scheele, and Torbern Olof Bergman, the distinctness of lead and bismuth became clear, and Claude François Geoffroy demonstrated in 1753 that this metal is distinct from lead and tin. [46] [49] [50] |
For 18th-century discoveries, around the time that Antoine Lavoisier first questioned the phlogiston theory, the recognition of a new "earth" has been regarded as being equivalent to the discovery of a new element (as was the general practice then). For some elements (e.g. Be, B, Na, Mg, Al, Si, K, Ca, Mn, Co, Ni, Zr, Mo), [51] this presents further difficulties as their compounds were widely known since medieval or even ancient times, even though the elements themselves were not. Since the true nature of those compounds was sometimes only gradually discovered, it is sometimes very difficult to name one specific discoverer. [1] [52] In such cases the first publication on their chemistry is noted, and a longer explanation given in the notes. [1] [52]
Z | Element | Observed or predicted | Isolated (widely known) | Notes | ||
---|---|---|---|---|---|---|
Year | By | Year | By | |||
15 | Phosphorus | 1669 | H. Brand | 1669 | H. Brand | Prepared and isolated from urine, it was the first element whose discovery date and discoverer are recorded. [53] Its name first appears in print in the work of Georg Kaspar Kirchmayer in 1676. Recognised as an element by Lavoisier. [1] |
1 | Hydrogen | 1671 | R. Boyle | 1671 | R. Boyle | Robert Boyle produced it by reacting iron filings with dilute acid. [54] [55] Henry Cavendish in 1766 was the first to distinguish H 2 from other gases. [56] Lavoisier named it in 1783. [57] [58] It was the first elemental gas known. |
11 | Sodium | 1702 | G. E. Stahl | 1807 | H. Davy | Georg Ernst Stahl obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702, [59] and Henri Louis Duhamel du Monceau was able to prove this difference in 1736. [60] Andreas Sigismund Marggraf again recognised the difference between soda ash and potash in 1758, but not all chemists accepted his conclusion. In 1797, Martin Heinrich Klaproth suggested the names natron and kali for the two alkalis (whence the symbols). Davy isolated sodium metal a few days after potassium, by using electrolysis on sodium hydroxide [61] and potash [62] respectively. |
19 | Potassium | 1702 | G. E. Stahl | 1807 | H. Davy | |
27 | Cobalt | 1735 | G. Brandt | 1735 | G. Brandt | Proved that the blue color of glass is due to a new kind of metal and not bismuth as thought previously. [63] |
20 | Calcium | 1739 | J. H. Pott | 1808 | H. Davy | Lime was known as a substance for centuries, but only in the 18th century was its chemical nature recognised. Pott recognised terra calcarea (calcareous earth) as an individual "earth" in his treatise of 1739. Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy suggested in 1787 that it was the oxide of an element. Davy isolated the metal electrochemically from quicklime. [1] |
14 | Silicon | 1739 | J. H. Pott | 1823 | J. Berzelius | Silicon compounds (rock crystals and glass) were known to the ancients, but its chemical investigation dates only to the 17th century. Johann Joachim Becher (of the phlogiston theory) identified silica as the terra vitrescibilis, and Johann Heinrich Pott recognised it as an individual "earth" in his treatise of 1739. [1] Silica appears as a "simple earth" in the Méthode de nomenclature chimique, and in 1789 Lavoisier concluded that the element must exist. [1] Davy thought in 1800 that silica was a compound, not an element, and in 1808 he proved this although he could not isolate the element, and suggested the name silicium. [64] [65] In 1811 Louis-Joseph Gay-Lussac and Louis-Jacques Thénard probably prepared impure silicon, [66] and Berzelius obtained the pure element in 1823. [67] The name was proposed to be changed to silicon by Thomas Thomson in 1817, and this was eventually accepted because of its analogies to boron and carbon. |
13 | Aluminium | 1746 | J. H. Pott | 1824 | H.C.Ørsted | Paracelsus recognised aluminis as separate from vitriol in 1570, and Andreas Libavius proposed in his 1597 treatise to name the unknown earth of alum alumina. In 1746, Johann Heinrich Pott published a treatise distinguishing alum from lime and chalk, and Marggraf precipitated the new earth in 1756. [1] Antoine Lavoisier predicted in 1787 that alumina is the oxide of an undiscovered element, and in 1808 Davy tried to decompose it. Although he failed, he proved Lavoisier correct and suggested the present name. [64] [68] Hans Christian Ørsted was the first to isolate metallic aluminium in 1824. [69] [70] |
28 | Nickel | 1751 | F. Cronstedt | 1751 | F. Cronstedt | Found by attempting to extract copper from the mineral known as fake copper (now known as niccolite). [71] |
12 | Magnesium | 1755 | J. Black | 1808 | H. Davy | Joseph Black observed that magnesia alba (MgO) was not quicklime (CaO) in 1755; until then, both substances had been confused. Davy isolated the metal electrochemically from magnesia. [72] |
9 | Fluorine | 1771 | W. Scheele | 1886 | H. Moissan | Fluorspar was described by Georgius Agricola in 1529. [73] Scheele studied fluorspar and correctly concluded it to be the lime (calcium) salt of an acid. [74] Radical fluorique appears on the list of elements in Lavoisier's Traité Élémentaire de Chimie from 1789, but radical muriatique also appears instead of chlorine. [75] André-Marie Ampère again predicted in 1810 that hydrofluoric acid contained an element analogous to chlorine, and between 1812 and 1886 many researchers tried to obtain it. It was eventually isolated by Moissan. [76] |
8 | Oxygen | 1771 | W. Scheele | 1771 | W. Scheele | Scheele obtained it by heating mercuric oxide and nitrates in 1771, but did not publish his findings until 1777. Joseph Priestley also prepared this new air by 1774, but only Lavoisier recognized it as a true element; he named it in 1777. [77] [78] Before him, Sendivogius had produced oxygen by heating saltpetre, correctly identifying it as the "food of life". [79] |
7 | Nitrogen | 1772 | D. Rutherford | 1772 | D. Rutherford | Rutherford discovered nitrogen while studying at the University of Edinburgh. [80] He showed that the air in which animals had breathed, even after removal of the exhaled carbon dioxide, was no longer able to burn a candle. Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley also studied the element at about the same time, and Lavoisier named it in 1775–6. [81] |
56 | Barium | 1772 | W. Scheele | 1808 | H. Davy | Scheele distinguished a new earth (BaO) in pyrolusite in 1772. He did not name his discovery; Guyton de Morveau suggested barote in 1782. [1] It was changed to baryte in the Méthode de nomenclature chimique of Louis-Bernard Guyton de Morveau, Antoine Lavoisier, Claude Louis Berthollet, and Antoine François, comte de Fourcroy (1787). Davy isolated the metal by electrolysis. [82] |
25 | Manganese | 1774 | W. Scheele | 1774 | J. G. Gahn | Distinguished pyrolusite as the calx of a new metal. Ignatius Gottfred Kaim might have isolated it in 1770, but there is uncertainty on that. It was isolated by reduction of manganese dioxide with carbon. Given its present name in 1779 by Guyton de Morveau; prior to that it was called magnesia. [1] [83] |
17 | Chlorine | 1774 | W. Scheele | 1774 | W. Scheele | Obtained it from hydrochloric acid, but thought it was an oxide. Only in 1808 did Humphry Davy recognize it as an element. [84] [85] |
42 | Molybdenum | 1778 | W. Scheele | 1788 | J. Hjelm | Scheele recognised the metal as a constituent of molybdena. [86] Before that, Axel Cronstedt had assumed that molybdena contained a new earth in 1758. [1] |
74 | Tungsten | 1781 | W. Scheele | 1783 | J. and F. Elhuyar | Scheele showed that scheelite (then called tungsten) was a salt of calcium with a new acid, which he called tungstic acid. The Elhuyars obtained tungstic acid from wolframite and reduced it with charcoal, naming the element "volfram". [1] [87] Since that time both names, tungsten and wolfram, have been used depending on language. [1] In 1949 IUPAC made wolfram the scientific name, but this was repealed after protest in 1951 in favour of recognising both names pending a further review (which never materialised). Currently only tungsten is recognised for use in English. [85] |
52 | Tellurium | 1782 | F.-J.M. von Reichenstein | 1798 | H. Klaproth | Muller observed it as an impurity in gold ores from Transylvania. [88] Klaproth isolated it in 1798. [85] |
38 | Strontium | 1787 | W. Cruikshank | 1808 | H. Davy | W. Cruikshank in 1787 and Adair Crawford in 1790 concluded that strontianite contained a new earth. It was eventually isolated electrochemically in 1808 by Davy. [89] |
5 | Boron | 1787 | L. Guyton de Morveau, A. Lavoisier, C. L. Berthollet, and A. de Fourcroy | 1809 | H. Davy | Borax was known from ancient times. In 1787, radical boracique appeared in the Méthode de nomenclature chimique of Louis-Bernard Guyton de Morveau, Antoine Lavoisier, Claude Louis Berthollet, and Antoine François, comte de Fourcroy. [1] It also appears in Lavoisier's Traité Élémentaire de Chimie from 1789. [75] In 1808, Lussac and Thénard announced a new element in sedative salt and named it bore. Davy announced the isolation of a new substance from boracic acid in 1809, naming it boracium. [90] As the element turned out not to be a metal, he revised his proposal to boron in 1812. [1] |
1789 | A. Lavoisier | Lavoisier writes the first modern list of chemical elements – containing 33 elements including light and heat but omitting Na, K (he was unsure of whether soda and potash without carbonic acid, i.e. Na2O and K2O, are simple substances or compounds like NH3), [91] Sr, Te; some elements were listed in the table as unextracted "radicals" (Cl, F, B) or as oxides (Ca, Mg, Ba, Al, Si). [75] He also redefines the term "element". Until then, no metals except mercury were considered elements. | ||||
40 | Zirconium | 1789 | H. Klaproth | 1824 | J. Berzelius | Martin Heinrich Klaproth identified a new oxide in zircon in 1789, [92] [93] and in 1808 Davy showed that this oxide has a metallic base although he could not isolate it. [64] [94] |
92 | Uranium | 1789 | H. Klaproth | 1841 | E.-M. Péligot | Klaproth mistakenly identified a uranium oxide obtained from pitchblende as the element itself and named it after the recently discovered planet Uranus. [95] [96] |
22 | Titanium | 1791 | W. Gregor | 1825 | J. Berzelius | Gregor found an oxide of a new metal in ilmenite; Klaproth independently discovered the element in rutile in 1795 and named it. The pure metallic form was only obtained in 1910 by Matthew A. Hunter. [97] [98] |
39 | Yttrium | 1794 | J. Gadolin | 1843 | H. Rose | Johan Gadolin discovered the earth in gadolinite in 1794. He did not name his discovery, but Andreas Ekeberg did so when he confirmed it in 1797. [1] Mosander showed later that its ore, yttria, contained more elements. [99] [100] In 1808, Davy showed that yttria is a metallic oxide, although he could not isolate the metal. [64] [101] Wöhler mistakenly thought he had isolated the metal in 1828 from a volatile chloride he supposed to be yttrium chloride, [102] [103] but Rose proved otherwise in 1843 and correctly isolated the element himself that year. |
24 | Chromium | 1797 | N. Vauquelin | 1798 | N. Vauquelin | Vauquelin analysed the composition of crocoite ore in 1797, and later isolated the metal by heating the oxide in a charcoal oven. [1] [104] [105] |
4 | Beryllium | 1798 | N. Vauquelin | 1828 | F. Wöhler and A. Bussy | Vauquelin discovered the oxide in beryl and emerald in 1798, and in 1808 Davy showed that this oxide has a metallic base although he could not isolate it. [64] [106] Vauquelin was uncertain about the name to give to the oxide: in 1798 he called it la terre du beril, but the journal editors named it glucine after the sweet taste of beryllium compounds (which are highly toxic). Johann Heinrich Friedrich Link proposed in 1799 to change the name from Glucine to Beryllerde or Berylline (because glucine resembled glycine), a suggestion taken up by Klaproth in 1800 in the form beryllina. Klaproth had independently worked on beryl and emerald and likewise concluded that a new element was present. The name beryllium for the element was first used by Wöhler upon its isolation (Davy used the name glucium). Both names beryllium and glucinium were used (the latter mostly in France) until IUPAC decided on the name beryllium in 1949. [1] |
23 | Vanadium | 1801 | A. M. del Río | 1867 | H. E. Roscoe | Andrés Manuel del Río found the metal (calling it erythronium) in vanadinite in 1801, but the claim was rejected after Hippolyte Victor Collet-Descotils dismissed it as chromium based on erroneous and superficial testing. [107] Nils Gabriel Sefström rediscovered the element in 1830 and named it vanadium. Friedrich Wöhler then showed that vanadium was identical to erythronium and thus that del Río had been right in the first place. [108] [109] Del Río then argued passionately that his old claim be recognised, but the element kept the name vanadium. [109] |
41 | Niobium | 1801 | C. Hatchett | 1864 | W. Blomstrand | Hatchett found the element in columbite ore and named it columbium. In 1809, W. H. Wollaston claimed that columbium and tantalum are identical, which proved to be false. [85] Heinrich Rose proved in 1844 that the element is distinct from tantalum, and renamed it niobium. American scientists generally used the name columbium, while European ones used niobium. Niobium was officially accepted by IUPAC in 1949. [110] |
73 | Tantalum | 1802 | G. Ekeberg | Ekeberg found another element in minerals similar to columbite, and named it after Tantalus from Greek mythology because of its inability to be dissolved by acids (just as Tantalus was tantalised by water that receded when he tried to drink it). [85] In 1809, W. H. Wollaston claimed that columbium and tantalum are identical, which proved to be false. [85] In 1844, Heinrich Rose proved that the elements were distinct and renamed columbium to niobium (Niobe is the daughter of Tantalus). [111] | ||
46 | Palladium | 1802 | W. H. Wollaston | 1802 | W. H. Wollaston | Wollaston discovered it in samples of platinum from South America, but did not publish his results immediately. He had intended to name it after the newly discovered asteroid, Ceres, but by the time he published his results in 1804, cerium had taken that name. Wollaston named it after the more recently discovered asteroid Pallas. [112] |
58 | Cerium | 1803 | H. Klaproth, J. Berzelius, and W. Hisinger | 1826 | G. Mosander | Berzelius and Hisinger discovered the element in ceria and named it after the newly discovered asteroid (then considered a planet), Ceres. Klaproth discovered it simultaneously and independently in some tantalum samples. Mosander proved later that the samples of all three researchers had at least another element in them, lanthanum. [113] |
76 | Osmium | 1803 | S. Tennant | 1803 | S. Tennant | Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium. [114] |
77 | Iridium | 1803 | S. Tennant and H.-V. Collet-Descotils | 1803 | S. Tennant | Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium, and published the iridium results in 1804. [115] Collet-Descotils also found iridium the same year, but not osmium. [85] |
45 | Rhodium | 1804 | H. Wollaston | 1804 | H. Wollaston | Wollaston discovered and isolated it from crude platinum samples from South America. [116] |
53 | Iodine | 1811 | B. Courtois | 1811 | B. Courtois | Courtois discovered it in the ashes of seaweed. [117] The name iode was given in French by Gay-Lussac and published in 1813. [52] Davy gave it the English name iodine in 1814. [52] |
3 | Lithium | 1817 | A. Arfwedson | 1821 | W. T. Brande | Arfwedson, a student of Berzelius, discovered the alkali in petalite. [118] Brande isolated it electrolytically from lithium oxide. [52] |
48 | Cadmium | 1817 | S. L Hermann, F. Stromeyer, and J.C.H. Roloff | 1817 | S. L Hermann, F. Stromeyer, and J.C.H. Roloff | All three found an unknown metal in a sample of zinc oxide from Silesia, but the name that Stromeyer gave became the accepted one. [119] |
34 | Selenium | 1817 | J. Berzelius and G. Gahn | 1817 | J. Berzelius and G. Gahn | While working with lead they discovered a substance that they thought was tellurium, but realized after more investigation that it was different. [120] |
35 | Bromine | 1825 | J. Balard and C. Löwig | 1825 | J. Balard and C. Löwig | They both discovered the element in the autumn of 1825. Balard published his results the next year, [121] but Löwig did not publish until 1827. [122] |
90 | Thorium | 1829 | J. Berzelius | 1914 | D. Lely, Jr. and L. Hamburger | Berzelius obtained the oxide of a new earth in thorite. [123] |
57 | Lanthanum | 1838 | G. Mosander | 1841 | G. Mosander | Mosander found a new element in samples of ceria and published his results in 1842, but later he showed that this lanthana contained four more elements. [124] |
60 | Neodymium | 1841 | G. Mosander | 1885 | C. A. von Welsbach | Discovered by Mosander and called didymium. Carl Auer von Welsbach later split it into two elements, praseodymium and neodymium. Neodymium had formed the greater part of the old didymium and received the prefix "neo-". [85] [125] |
68 | Erbium | 1843 | G. Mosander | 1879 | T. Cleve | Mosander managed to split the old yttria into yttria proper and erbia, and later terbia too. [126] The names underwent some confusion: Mosander's erbia was yellow and his terbia was red. But in 1860, Nils Johan Berlin could only find the rose-coloured earth, confusingly renamed as erbia, and questioned the existence of the yellow earth. Marc Delafontaine adopted Berlin's nomenclature where erbia was the rose-coloured earth, but proved that the yellow earth also existed. At the prompting of Jean Charles Galissard de Marignac, he named the yellow earth terbia; thus Mosander's names were swapped from his original choices. [52] |
65 | Terbium | 1843 | G. Mosander | 1886 | J.C.G. de Marignac | Mosander managed to split the old yttria into yttria proper and erbia, and later terbia too. [127] |
44 | Ruthenium | 1844 | K. Claus | 1844 | K. Claus | Gottfried Wilhelm Osann thought that he found three new metals in Russian platinum samples in 1826, which he named polinium, pluranium, and ruthenium in 1828. But his results were questioned and he did not have enough quantities to isolate them, so he withdrew his claims in 1829. [128] However, in 1844 Karl Karlovich Klaus confirmed that there was one new metal, and reused Osann's name "ruthenium". [129] |
55 | Caesium | 1860 | R. Bunsen and R. Kirchhoff | 1882 | C. Setterberg | Bunsen and Kirchhoff were the first to suggest finding new elements by spectrum analysis. They discovered caesium by its two blue emission lines in a sample of Dürkheim mineral water. [130] The pure metal was eventually isolated in 1882 by Setterberg. [131] |
37 | Rubidium | 1861 | R. Bunsen and G. R. Kirchhoff | 1863 | R. Bunsen | Bunsen and Kirchhoff discovered it just a few months after caesium, by observing new spectral lines in the mineral lepidolite. [132] The metal was isolated by Bunsen around 1863. [52] |
81 | Thallium | 1861 | W. Crookes | 1862 | C.-A. Lamy | Shortly after the discovery of rubidium, Crookes found a new green line in a selenium sample; later that year, Lamy found the element to be metallic. [133] |
49 | Indium | 1863 | F. Reich and T. Richter | 1864 | T. Richter | Reich and Richter first identified it in sphalerite by its bright indigo-blue spectroscopic emission line. [134] Richter isolated the metal the next year. [52] |
2 | Helium | 1868 | N. Lockyer | 1895 | W. Ramsay, T. Cleve, and N. Langlet | P. Janssen and Lockyer observed independently a yellow line in the solar spectrum that did not match any other element. However, only Lockyer made the correct conclusion that it was due to a new element. This was the first observation of a noble gas, located in the Sun. Years later after the isolation of argon on Earth, Ramsay, Cleve, and Langlet observed independently helium trapped in cleveite. [135] |
1869 | D. I. Mendeleev | Mendeleev arranges the 63 elements known at that time (omitting terbium, as chemists were unsure of its existence, and helium, as it was not found on Earth) into the first modern periodic table and correctly predicts several others. | ||||
31 | Gallium | 1875 | P. E. L. de Boisbaudran | 1878 | P. E. L. de Boisbaudran and E. Jungfleisch | Boisbaudran observed on a pyrenea blende sample some emission lines corresponding to the eka-aluminium that was predicted by Mendeleev in 1871. He and Jungfleisch isolated the metal three years later by electrolysis. [136] [137] [52] |
70 | Ytterbium | 1878 | J.C.G. de Marignac | 1906 | C. A. von Welsbach | On October 22, 1878, Marignac reported splitting terbia into two new earths, terbia proper and ytterbia. [138] |
67 | Holmium | 1878 | J.-L. Soret and M. Delafontaine | 1879 | T. Cleve | Soret found it in samarskite and later, Per Teodor Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium. Delafontaine's philippium turned out to be identical to what Soret found. [139] [140] |
21 | Scandium | 1879 | F. Nilson | 1879 | F. Nilson | Nilson split Marignac's ytterbia into pure ytterbia and a new element that matched Mendeleev's 1871 predicted eka-boron. [141] |
69 | Thulium | 1879 | T. Cleve | 1879 | T. Cleve | Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium. [142] |
62 | Samarium | 1879 | P.E.L. de Boisbaudran | 1879 | P.E.L. de Boisbaudran | Boisbaudran noted a new earth in samarskite and named it samaria after the mineral. [143] |
64 | Gadolinium | 1880 | J. C. G. de Marignac | 1886 | P.E.L. de Boisbaudran | Marignac initially observed the new earth in terbia, and later Boisbaudran obtained a pure sample from samarskite. [144] |
59 | Praseodymium | 1885 | C. A. von Welsbach | Carl Auer von Welsbach discovered it in Mosander's didymia. [145] | ||
32 | Germanium | 1886 | C. A. Winkler | In February 1886 Winkler found in argyrodite the eka-silicon that Mendeleev had predicted in 1871. [146] | ||
66 | Dysprosium | 1886 | P.E.L. de Boisbaudran | 1905 | G. Urbain | De Boisbaudran found a new earth in erbia. [147] |
18 | Argon | 1894 | Lord Rayleigh and W. Ramsay | 1894 | Lord Rayleigh and W. Ramsay | They discovered the gas by comparing the molecular weights of nitrogen prepared by liquefaction from air and nitrogen prepared by chemical means. It is the first noble gas to be isolated. [148] |
63 | Europium | 1896 | E.-A. Demarçay | 1901 | E.-A. Demarçay | Demarçay found spectral lines of a new element in Lecoq's samarium, and separated this element several years later. [149] |
36 | Krypton | 1898 | W. Ramsay and W. Travers | 1898 | W. Ramsay and W. Travers | On May 30, 1898, Ramsay separated a noble gas from liquid argon by difference in boiling point. [150] |
10 | Neon | 1898 | W. Ramsay and W. Travers | 1898 | W. Ramsay and W. Travers | In June 1898 Ramsay separated a new noble gas from liquid argon by difference in boiling point. [150] |
54 | Xenon | 1898 | W. Ramsay and W. Travers | 1898 | W. Ramsay and W. Travers | On July 12, 1898, Ramsay separated a third noble gas within three weeks, from liquid argon by difference in boiling point. [151] |
84 | Polonium | 1898 | P. and M. Curie | 1902 | W. Marckwald | In an experiment done on July 13, 1898, the Curies noted an increased radioactivity in the uranium obtained from pitchblende, which they ascribed to an unknown element. Independently rediscovered and isolated in 1902 by Marckwald, who named it radiotellurium. [152] |
88 | Radium | 1898 | P. and M. Curie | 1902 | M. Curie | The Curies reported on December 26, 1898, a new element different from polonium, which Marie later isolated from uraninite. [153] |
86 | Radon | 1899 | E. Rutherford and R. B. Owens | 1910 | W. Ramsay and R. Whytlaw-Gray | Rutherford and Owens discovered a radioactive gas resulting from the radioactive decay of thorium, isolated later by Ramsay and Gray. In 1900, Friedrich Ernst Dorn discovered a longer-lived isotope of the same gas from the radioactive decay of radium. Since "radon" was first used to specifically designate Dorn's isotope before it became the name for the element, he is often mistakenly given credit for the latter instead of the former. [154] [155] |
89 | Actinium | 1902 | F. O. Giesel | 1903 | F. O. Giesel | Giesel obtained from pitchblende a substance that had properties similar to those of lanthanum and named it emanium. [156] André-Louis Debierne had previously (in 1899 and 1900) reported the discovery of a new element actinium that was supposedly similar to titanium and thorium, which cannot have included much actual element 89. But by 1904, when Giesel and Debierne met, both had radiochemically pure element 89, and so Debierne has generally been given credit for the discovery. [157] |
71 | Lutetium | 1906 | C. A. von Welsbach and G. Urbain | 1906 | C. A. von Welsbach | von Welsbach proved that the old ytterbium also contained a new element, which he named cassiopeium (he renamed the larger part of the old ytterbium to aldebaranium). Urbain also proved this at about the same time (von Welsbach's paper was published first, but Urbain sent his to the editor first), naming the new element lutetium and the old one neoytterbium (which later reverted to ytterbium). However, Urbain's samples were very impure and only contained trace quantities of the new element. Despite this, his chosen name lutetium was adopted by the International Committee of Atomic Weights, whose membership included Urbain. The German Atomic Weights Commission adopted cassiopeium for the next forty years. Finally in 1949 IUPAC decided in favour of the name lutetium as it was more often used. [85] [158] |
75 | Rhenium | 1908 | M. Ogawa | 1919 | M. Ogawa | Masataka Ogawa found it in thorianite in 1908, but assigned it as element 43 and named it nipponium. (Elements 43 and 75 are in the same group of the periodic table.) [159] Because of the erroneous assignment, and because some of his key results were published only in Japanese, his claim was not widely recognised. However, the optical emission spectrum described by Ogawa and the X-ray photographic plate for one of his samples match element 75, and his claim has thus been rehabilitated in much of the modern literature. [160] In 1925 Walter Noddack, Ida Eva Tacke and Otto Berg announced its separation from gadolinite, identified it correctly as element 75, and gave it the present name. [161] [162] |
91 | Protactinium | 1913 | O. H. Göhring and K. Fajans | 1927 | A. von Grosse | The two obtained the first isotope of this element, 234mPa, that had been predicted by Mendeleev in 1871 as a member of the natural decay of 238U: they named it brevium. A longer-lived isotope 231Pa was found in 1918 by Otto Hahn and Lise Meitner, and was named by them protoactinium: since it is longer-lived, it gave the element its name. Protoactinium was changed to protactinium in 1949. [163] Originally isolated in 1900 by William Crookes, who nevertheless did not recognize that it was a new element. [164] |
72 | Hafnium | 1922 | D. Coster and G. von Hevesy | 1922 | D. Coster and G. von Hevesy | Georges Urbain claimed to have found the element in rare-earth residues, while Vladimir Vernadsky independently found it in orthite. Neither claim was confirmed due to World War I, and neither could be confirmed later, as the chemistry they reported does not match that now known for hafnium. After the war, Coster and Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon. [165] Hafnium was the last stable element to be discovered (noting however the difficulties regarding the discovery of rhenium). |
43 | Technetium | 1937 | C. Perrier and E. Segrè | 1937 | C. Perrier & E. Segrè | The two discovered a new element in a molybdenum sample that was used in a cyclotron, the first element to be discovered by synthesis. It had been predicted by Mendeleev in 1871 as eka-manganese. [166] [167] [168] In 1952, Paul W. Merrill found its spectral lines in S-type red giants. [169] Minuscule trace quantities were finally found on Earth in 1962 by B. T. Kenna and Paul K. Kuroda: they isolated it from Belgian Congo pitchblende, where it occurs as a spontaneous fission product of uranium. [170] The Noddacks (rediscoverers of rhenium) claimed to have discovered element 43 in 1925 as well and named it masurium (after Masuria), but their claims were disproven by Kuroda, who calculated that there cannot have been enough technetium in their samples to have enabled a true detection. [171] |
87 | Francium | 1939 | M. Perey | Perey discovered it as a decay product of 227Ac. [172] Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well. [173] Before Perey, it is likely that Stefan Meyer, Viktor F. Hess, and Friedrich Paneth had observed the decay of 227Ac to 223Fr in Vienna in 1914, but they could not follow up and secure their work because of the outbreak of World War I. [173] | ||
93 | Neptunium | 1940 | E.M. McMillan and H. Abelson | Obtained by irradiating uranium with neutrons, it was the first transuranium element discovered. [174] Shortly before that, Yoshio Nishina and Kenjiro Kimura discovered the uranium isotope 237U and found that it beta decays into 23793, but were unable to measure the activity of the element 93 product because its half-life was too long. McMillan and Abelson succeeded because they used 239U, as 23993 has a much shorter half-life. [175] McMillan and Abelson found that 23993 itself undergoes beta decay and must produce an isotope of element 94, but the quantities they used were not enough to isolate and identify element 94 along with 93. [176] Natural traces were found in Belgian Congo pitchblende by D. F. Peppard et al. in 1952. [177] | ||
85 | Astatine | 1940 | D. R. Corson, K. R. MacKenzie and E. Segrè | Obtained by bombarding bismuth with alpha particles. [178] In 1943, Berta Karlik and Traude Bernert found it in nature; due to World War II, they were initially unaware of Corson et al.'s results. [179] Horia Hulubei and Yvette Cauchois had previously claimed its discovery as a natural radioelement from 1936, naming it dor: they likely did have the isotope 218At, and probably did have enough sensitivity to distinguish its spectral lines. But they could not chemically identify their discovery, and their work was doubted because of an earlier false claim by Hulubei to having discovered element 87. [180] [181] | ||
94 | Plutonium | 1941 | Glenn T. Seaborg, Arthur C. Wahl, W. Kennedy and E.M. McMillan | Prepared by bombardment of uranium with deuterons. [182] Seaborg and Morris L. Perlman then found it as traces in natural Canadian pitchblende in 1941–1942, though this work was kept secret until 1948. [183] | ||
96 | Curium | 1944 | Glenn T. Seaborg, Ralph A. James and Albert Ghiorso | Prepared by bombarding plutonium with alpha particles during the Manhattan Project [184] | ||
95 | Americium | 1944 | G. T. Seaborg, R. A. James, O. Morgan and A. Ghiorso | Prepared by irradiating plutonium with neutrons during the Manhattan Project. [185] | ||
61 | Promethium | 1945 | Charles D. Coryell, Jacob A. Marinsky, and Lawrence E. Glendenin | 1945 | Charles D. Coryell, Jacob A. Marinsky, and Lawrence E. Glendenin [186] [187] | It was probably first prepared at the Ohio State University in 1942 by bombarding neodymium and praseodymium with neutrons, but separation of the element could not be carried out. Isolation was performed under the Manhattan Project in 1945. [188] Found on Earth in trace quantities by Olavi Erämetsä in 1965; so far, promethium is the most recent element to have been found on Earth. [189] |
97 | Berkelium | 1949 | G. Thompson, A. Ghiorso and G. T. Seaborg (University of California, Berkeley) | Created by bombardment of americium with alpha particles. [190] | ||
98 | Californium | 1950 | S. G. Thompson, K. Street, Jr., A. Ghiorso and G. T. Seaborg (University of California, Berkeley) | Bombardment of curium with alpha particles. [191] | ||
99 | Einsteinium | 1952 | A. Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory and University of California, Berkeley) | Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons; kept secret for several years. [192] | ||
100 | Fermium | 1953 | A. Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory and University of California, Berkeley) | Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons; first identified in early 1953; kept secret for several years. [193] | ||
101 | Mendelevium | 1955 | A. Ghiorso, G. Harvey, G. R. Choppin, S. G. Thompson and G. T. Seaborg (Berkeley Radiation Laboratory) | Prepared by bombardment of einsteinium with alpha particles. [194] | ||
103 | Lawrencium | 1961 | A. Ghiorso, T. Sikkeland, E. Larsh and M. Latimer (Berkeley Radiation Laboratory) | First prepared by bombardment of californium with boron atoms. [195] | ||
102 | Nobelium | 1965 | E. D. Donets, V. A. Shchegolev and V. A. Ermakov (JINR in Dubna) | First prepared by bombardment of uranium with neon atoms [196] | ||
104 | Rutherfordium | 1969 | A. Ghiorso et al. (Berkeley Radiation Laboratory) and I. Zvara et al. (JINR in Dubna) | Prepared by bombardment of californium with carbon atoms by Albert Ghiorso's team and by bombardment of plutonium with neon atoms by Zvara's team. [197] | ||
105 | Dubnium | 1970 | A. Ghiorso et al. (Berkeley Radiation Laboratory) and V. A. Druin et al. (JINR in Dubna) | Prepared by bombardment of californium with nitrogen atoms by Ghiorso's team and by bombardment of americium with neon atoms by Druin's team. [198] | ||
106 | Seaborgium | 1974 | A. Ghiorso et al. (Berkeley Radiation Laboratory) | Prepared by bombardment of californium with oxygen atoms. [199] | ||
107 | Bohrium | 1981 | G.Münzenberg et al. (GSI in Darmstadt) | Obtained by bombarding bismuth with chromium. [200] | ||
109 | Meitnerium | 1982 | G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt) | Prepared by bombardment of bismuth with iron atoms. [201] | ||
108 | Hassium | 1984 | G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt) | Prepared by bombardment of lead with iron atoms [202] | ||
110 | Darmstadtium | 1994 | S. Hofmann et al. (GSI in Darmstadt) | Prepared by bombardment of lead with nickel [203] | ||
111 | Roentgenium | 1994 | S. Hofmann et al. (GSI in Darmstadt) | Prepared by bombardment of bismuth with nickel [204] | ||
112 | Copernicium | 1996 | S. Hofmann et al. (GSI in Darmstadt) | Prepared by bombardment of lead with zinc. [205] [206] | ||
114 | Flerovium | 1999 | Y. Oganessian et al. (JINR in Dubna) | Prepared by bombardment of plutonium with calcium. It may have already been found at Dubna in 1998, but that result has not been confirmed. [207] | ||
116 | Livermorium | 2000 | Y. Oganessian et al. (JINR in Dubna) | Prepared by bombardment of curium with calcium [208] | ||
118 | Oganesson | 2002 | Y. Oganessian et al. (JINR in Dubna) | Prepared by bombardment of californium with calcium [209] | ||
115 | Moscovium | 2003 | Y. Oganessian et al. (JINR in Dubna) | Prepared by bombardment of americium with calcium [210] | ||
113 | Nihonium | 2003–2004 | Y. Oganessian et al. (JINR in Dubna) and K. Morita et al. (RIKEN in Wako, Japan) | Prepared by decay of moscovium by Oganessian's team [210] and bombardment of bismuth with zinc by Morita's team. [211] Both teams began their experiments in 2003; Oganessian's team detected its first atom in 2003, but Morita's only in 2004. However, both teams published in 2004. | ||
117 | Tennessine | 2009 | Y. Oganessian et al. (JINR in Dubna) | Prepared by bombardment of berkelium with calcium [212] |
Bohrium is a synthetic chemical element; it has symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in particle accelerators but is not found in nature. All known isotopes of bohrium are highly radioactive; the most stable known isotope is 270Bh with a half-life of approximately 2.4 minutes, though the unconfirmed 278Bh may have a longer half-life of about 11.5 minutes.
Meitnerium is a synthetic chemical element; it has symbol Mt and atomic number 109. It is an extremely radioactive synthetic element. The most stable known isotope, meitnerium-278, has a half-life of 4.5 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds. The GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany, first created this element in 1982. It is named after Lise Meitner.
Rutherfordium is a synthetic chemical element; it has symbol Rf and atomic number 104. It is named after physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be made in a particle accelerator. It is radioactive; the most stable known isotope, 267Rf, has a half-life of about 48 minutes.
Darmstadtium is a synthetic chemical element; it has symbol Ds and atomic number 110. It is extremely radioactive: the most stable known isotope, darmstadtium-281, has a half-life of approximately 14 seconds. Darmstadtium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research in the city of Darmstadt, Germany, after which it was named.
Livermorium is a synthetic chemical element; it has symbol Lv and atomic number 116. It is an extremely radioactive element that has only been created in a laboratory setting and has not been observed in nature. The element is named after the Lawrence Livermore National Laboratory in the United States, which collaborated with the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, to discover livermorium during experiments conducted between 2000 and 2006. The name of the laboratory refers to the city of Livermore, California, where it is located, which in turn was named after the rancher and landowner Robert Livermore. The name was adopted by IUPAC on May 30, 2012. Five isotopes of livermorium are known, with mass numbers of 288 and 290–293 inclusive; the longest-lived among them is livermorium-293 with a half-life of about 80 milliseconds. A sixth possible isotope with mass number 294 has been reported but not yet confirmed.
Oganesson is a synthetic chemical element; it has symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, near Moscow, Russia, by a joint team of Russian and American scientists. In December 2015, it was recognized as one of four new elements by the Joint Working Party of the international scientific bodies IUPAC and IUPAP. It was formally named on 28 November 2016. The name honors the nuclear physicist Yuri Oganessian, who played a leading role in the discovery of the heaviest elements in the periodic table. It is one of only two elements named after a person who was alive at the time of naming, the other being seaborgium, and the only element whose eponym is alive as of 2024.
In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. Its theoretical existence is attributed to stabilizing effects of predicted "magic numbers" of protons and neutrons in the superheavy mass region.
Unbinilium, also known as eka-radium or element 120, is a hypothetical chemical element; it has symbol Ubn and atomic number 120. Unbinilium and Ubn are the temporary systematic IUPAC name and symbol, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be an s-block element, an alkaline earth metal, and the second element in the eighth period. It has attracted attention because of some predictions that it may be in the island of stability.
Moscovium is a synthetic chemical element; it has symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. In December 2015, it was recognized as one of four new elements by the Joint Working Party of international scientific bodies IUPAC and IUPAP. On 28 November 2016, it was officially named after the Moscow Oblast, in which the JINR is situated.
Tennessine is a synthetic chemical element; it has symbol Ts and atomic number 117. It has the second-highest atomic number and joint-highest atomic mass of all known elements and is the penultimate element of the 7th period of the periodic table. It is named after the region of Tennessee, where key research institutions involved in its discovery are located.
Copernicium is a synthetic chemical element; it has symbol Cn and atomic number 112. Its known isotopes are extremely radioactive, and have only been created in a laboratory. The most stable known isotope, copernicium-285, has a half-life of approximately 30 seconds. Copernicium was first created in 1996 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It was named after the astronomer Nicolaus Copernicus on his 537th birthday.
Nihonium is a synthetic chemical element; it has the symbol Nh and atomic number 113. It is extremely radioactive: its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13.
Superheavy elements, also known as transactinide elements, transactinides, or super-heavy elements, or superheavies for short, are the chemical elements with atomic number greater than 103. The superheavy elements are those beyond the actinides in the periodic table; the last actinide is lawrencium. By definition, superheavy elements are also transuranium elements, i.e., having atomic numbers greater than that of uranium (92). Depending on the definition of group 3 adopted by authors, lawrencium may also be included to complete the 6d series.
Rutherfordium (104Rf) is a synthetic element and thus has no stable isotopes. A standard atomic weight cannot be given. The first isotope to be synthesized was either 259Rf in 1966 or 257Rf in 1969. There are 16 known radioisotopes from 253Rf to 270Rf and several isomers. The longest-lived isotope is 267Rf with a half-life of 48 minutes, and the longest-lived isomer is 263mRf with a half-life of 8 seconds.
Hassium (108Hs) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 265Hs in 1984. There are 13 known isotopes from 263Hs to 277Hs and up to six isomers. The most stable known isotope is 271Hs, with a half-life of about 46 seconds, though this assignment is not definite due to uncertainty arising from a low number of measurements. The isotopes 269Hs and 270Hs respectively have half-lives of about 12 seconds and 7.6 seconds. It is also possible that the isomer 277mHs is more stable than these, with a reported half-life 130±100 seconds, but only one event of decay of this isotope has been registered as of 2016.
Copernicium (112Cn) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 277Cn in 1996. There are 6 known radioisotopes ; the longest-lived isotope is 285Cn with a half-life of 30 seconds.
Flerovium (114Fl) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 289Fl in 1999. Flerovium has six known isotopes, along with the unconfirmed 290Fl, and possibly two nuclear isomers. The longest-lived isotope is 289Fl with a half-life of 1.9 seconds, but 290Fl may have a longer half-life of 19 seconds.
Yuri Tsolakovich Oganessian is a Soviet and Russian nuclear physicist who is best known as a researcher of superheavy chemical elements. He has led the discovery of multiple elements of the periodic table. He succeeded Georgy Flyorov as director of the Flyorov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research in 1989 and is now its scientific director. The heaviest element known of the periodic table, oganesson, is named after him, only the second time that an element was named after a living person.
Unbiunium, also known as eka-actinium or element 121, is a hypothetical chemical element; it has symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be the first of the superactinides, and the third element in the eighth period. It has attracted attention because of some predictions that it may be in the island of stability. It is also likely to be the first of a new g-block of elements.
Probably metallic antimony was being produced in Germany in Biringuccio's time, for later in this chapter he mentions importation of cakes of the smelted (or melted) metal to alloy with pewter or bell metal.
...today's inclination to re-evaluate the work of Delafontaine and Soret has led justifiably to their being included as co-discoverers of holmium.